Positive rules we really really like?

[Duke Speedy of Leighton]

Okay, here are the rules, you cannot be negative about a rule set just because...
Let's have a thread where we post the great things about rules we have played. Hell you don't even have to like the rules in question just and aspect of them!
If someone else doesn't like that bit, fine, but they have to come up with a better alternative...
Here's my starters.
1 Principles of War. - initial map orders and written notes about how generals then act (Attack hill W then hold).
2 Black Powder and Hail Caesar 'Blunder table'.
3 Fire and Fury Movement, Morale and shooting tables word choices (sliddadle, tardy advance etc.).
4 DBA1s twelve element armies and PIP dice.
5 Scramble's midair collision table.
6 Blood Bowl FUMBLE!
7 Flames of War hitting your opponent's troops based on how bad he is, not how good you are.
8 The d1000 mutation table in the original GW chaos books!
9 AK47 political table and roll your own flag table.
10 Crossfire's lack of turn sequencing and... BANG! Shooting as your opponet moves towards you by calling the shot in his move!

[nikharwood]

Instant response while I think properly:

Mordheim: Diving Charge  

I love this rule so much I made it my mission in life to attempt at least one of these per game....I even did it with my Kislevite Bear at Gang Wars campaign weekend at Warhammer World one year - it featured in Fanatic Magazine  

EDIT: just found the evidence & pics here: http://www.specialist-arms.com/fanatic/07cta.pdf  

[mollinary]

To the Last Gaiter Button - only change from March (manoeuvre) column to tactical formation once in a battle.   Really defines your reserves from your front line, and makes you think much more carefully about when you commit troops.  Simple, and totally brilliant.

Mollinary

[Nosher]

1.  Agreed Principles of War set up and orders

2.  Principles of war command rating on 1d4, 1d6 and 1dav - sh*t generals stay sh*t generals

3.  Tea Break card in IABSM

4.  "That's not on the map!" card in Maurice

5.  Warmaster command system (CV ratings) and the subleties of command

6.  SAGA Battleboard System

7.  The vagaries of the scatter on a dropped/fumbled pass in Bloodbowl

8.  FoG Army Books - great combination of 'potted' overview, uniform plates etc which is really helpful when looking at taking on a new period 

9.  The explosion damage card in Wings of War when it happens to an opponent and when it happens to me

[Shecky]

1. I'll second the tea break card in many of the TFL rules.
2. Command dice and variable phases in might & reason. You only have a certain number of dice per turn to assist with activation, re-rolls, etc. per turn but the turn can be anywhere from 1-4 phases long.
3. Para drops in the old command decision. Put numbered chits on a ruler, hold it above the drop zone on the table and turn over the ruler letting the chits fall. Where they land is where the stands appear. If the fit lands face down the unit takes a hit.
4. Movement in Napoleon at War. Measurement is done by the flag stand. Makes wheeling so much easier to measure.

[Luddite]

Pretty much everything about Fire & Fury.  Faultless ruleset.

Pretty much everything about DBx.  Fiddly, riddled with faults, but utterly compelling tournament play.  PiP mechanic iwas revolutionary and elegant (now copied by the likes of Warmaster and XXCommander.  (That said, the current version of DBA out for playtest at the moment fixes all the 'fiddly' issues and i think it's the best iteration so far).

Legends of the Old West* - dripping with period flavour, nice simple and effective skirmish play, great tournament set that really engages you with your 'posse'. (and Mordheim, LotR, Necromunda, etc.)

Crossfire - for breaking the IGOUGO tyranny in a way that works.

Spearhead - for is command system that forces you to plan properly and stick to your plan to 'see it through'.

Ambush Alley (et. al.) - for doing asymmetrical warfare so well.

[Last Hussar]

Polyhedral dice with opposide rolls in Dirtside - the better the gun or armour the bigger die you get.  Attack>defence to hit

[mollinary]

Fire and Fury and Regimental Fire and Fury - combining morale and manoeuvre in simple, single, elegant mechanism.

Mollinary

[Duke Speedy of Leighton]

Couple of left fielders here:
11 B17 Queen of the Skies, depending on where you are in the formation means more enemy planes (NEVER EVER BE TAIL END CHARLIE!)
12 Volley and Bayonet Road to Glory, randomized entry system (you pick one division in four arriving turn one, facing an enemy who has picked a full deployment; but the player with less forces gets more victory points!
hmm running theme of randommess in my choices!

[Grenadier]

Ah, #11. Was that the solo board game where the player was just one B-17? I created my own variant but I called it "Gotha" where, obviously, it was WWI and Sopwith camels attacked! Great fun.

[Duke Speedy of Leighton]

That's the one, we usually played one man on the B17, one as German; there was one night where we ended up with about 8 players B17s flying in formation, brutal! 

[FierceKitty]

DBx's "fast" troop class and its effects; the champion reaction tests and consquent paralysis of units in "Rising Sun"; the exaggerated but rntertaining danger of accidental explosions with irregula artillery in "White Man's Burden" (got me yesterday).

[Aart Brouwer]

Black Powder: swift melee resolution, functionality of Special Rules
Spearhead: written orders
Crossfire: just over-all brilliant, if I have to pick one thing it's that it has no Ãœber-armour
Pike & Shotte: use of artillery feels just right

Cheers,
Aart

[Paint it Pink]

OGRE/GEV: one big unit versus lots of little ones, classic game no rule out of place.

BattleTech, big giant stompy walking machines going Mano-o-mano, basic set still rocks.

[Fenton]

Black Powder: swift melee resolution, functionality of Special Rules
Spearhead: written orders
Crossfire: just over-all brilliant, if I have to pick one thing it's that it has no Ãœber-armour
Pike & Shotte: use of artillery feels just right

Cheers,
Aart

Crossfire for me to though we did change the armour rules which we thought didnt work too well, and we wanted to make them slightly easier for the Bulge campaign we wanted to run